Traffic direction pavement markers, paintings, curbing, raised islands, rumble bars and high buttons have been used and are being used to assist drivers of vehicles, soon enough in their decision times to make timely important and/or critical maneuvers in many locations and especially in potentially hazardous locations along highways, roadways, and city streets. Drivers today observe spaced lane markers to determine the left and right sides of a traffic lane. Painted stripes are also used to aid drivers in their determinations of the left and right sides of a traffic lane.
Although paint and/or small spaced lane markers have also been used to make drivers more acutely aware of the lane ahead being changed in size and/or in direction or having a departing lane, generally different pavement level and near pavement level markings, paintings, rumble bars, curbings, raised larger buttons, raised islands, and raised gore areas are utilized by those persons designing, making, and maintaining the highways, roadways and city streets. However, recent considerations and studies of accidents which occurred when a motorcycle, car, or truck ran over curbing, a raised island, a raised gore area, and/or higher and larger buttons, have indicated that these markers, while serving their initial purpose, have also caused some serious accidents, when a driver fails to direct his or her vehicle soon enough and strikes these higher markings, when trying to stay in a lane, or to make a change in direction of the lane, to leave a lane, to enter a lane, or to avoid a lane. As a consequence of these considerations, some of which resulted from successful legal suits undertaken by injured persons, who received sizeable sums, via settlements and/or judgments, some state regulations and specifications have been changed. No longer will raised islands, raised gore areas, curbing, and higher and larger buttons be used. Therefore, there is a need for traffic control devices to be located at pavement levels to aid a motorist, yet not cause the motorist trouble if he or she unwantedly drives a vehicle over the traffic control devices.
No longer do the highway designers, engineers, and other personnel concerned with pavement level or near pavement level markers, want to specify the hard round larger buttons, which have been referred to as launching pads. Nor do they want high curbings, high islands, or higher type rumble bars. The latter are elongated bars having a transverse cross section formed with a curved top determined by a comparatively large radius, and the ends slope downwardly. They are positioned ahead of bridge abutments, wall dividers, road edge rails and fences, and signs to warn a motorist of the impending danger of hitting these formidable structures, so the motorists will promptly and timely redirect his or her vehicle back into the traffic lane to thereby clear such a structure.
In reference to selected United States patents some of the prior traffic control devices located at or near pavement level are set forth in these patents:
U.S. Pat. No. 3,332,327 of 1967 wherein Sidney Heenan disclosed his pavement marker secured to a roadway surface to return the incident light coming from vehicle headlights as refracted light in a parallel direction. The obverse face of this pavement marker made an acute angle of at least fifteen degrees with the base and rose above the roadway surface to maintain an adequate optical effectiveness during service, while allowing wiping of this obverse face by tire contacts of passing vehicles. The internal reflective elements were of the cube corner type. The overall shape involved a larger rectangular base, a small rectangular top, with surrounding fifteen degree inwardly sloping sides;
U.S. Pat. No. 3,485,148 of 1969, wherein Sidney Heenan disclosed his pavement markers with selectively replaceable reflectors. These markers were rectangular at a large base and then sloped upwardly at fifteen degrees to a small rectangular top. The replaceable reflectors incorporated cube corner type internal reflectors;
U.S. Pat. No. 3,785,719 of 1974, wherein Nelson Jonnes disclosed his roadway lane delineator having an elastomeric reflective portion supported by a base portion, and having a retro-reflective material positioned on the reflective portion. The elastomeric portions deflected under tire pressure or snow plow pressures, so the reflection capabilities had a longer active life, before the retro-reflective materials were replaced, or the entire delineator was replaced;
U.S. Pat. No. 3,836,226 of 1974, wherein James A. Cechetini disclosed his reflective pavement marker having an inside trapezoidal support block of glass spheres in a cement binder surrounded by a reflective acute angled side grid having diamond shaped reflectors. Then they together were covered by a layer of light-refractive translucent material also serving in the light reflection of vehicle headlights and protecting the side grid and the support block;
U.S. Pat. No. 3,922,066 of 1975, wherein Howard A. Schaefer disclosed his reflective roadway marker made of glass formed to provide an optical system to reflect vehicle headlights, and to receive internally and lowly, a potting compound used in securing this marker to the roadway. In one embodiment, in the top view, the marker appears as an elongated ellipse, and in one long side view as a dome;
U.S. Pat. No. Re. 31,291 of 1983, wherein Ludwig Eigenmann disclosed his road surface marking prefabricated tape material having retroreflective composite elements associated therewith. The latter were positioned high enough to reflect vehicles' headlights and they contained cube corner reflectors; and
U.S. Pat. No. 4,428,320 of 1984, wherein David W. Oplt disclosed his reflective paving marker used to delineate traffic lanes. A light weight molded plastic support structure had a bottom with slight recesses to create a grip in the adhesive attachment of the marker to the pavement. Also this light weight support had inclined slight recesses to receive thin strips of reflective polycarbonate tape which reflected vehicle headlights. The recesses were deep enough to protect this reflective tape from the abrasive effects of the tires of passing vehicles.
Although the currently used markers and stripes, and these patents indicate the progress made in providing pavement markers, there remained a need for pavement markers which could be used at locations where the motorist would be required to do more than proceed generally ahead on selected parallel traffic lanes, which were well marked, on a highway. Such locations are many, for example: when a motorist in operating his or her vehicle, is leaving or returning to a highway, making left turns by entering pockets, merging from two lanes into one, approaching a danger area such as a blind driveway, arriving at a wider street expanse having a common middle lane for left turns, approaching nearby lane structures, such as bridge abutments, traffic control walls or barriers, sign posts, light posts, and approaching ditches, excavations and holes.